Jim Charter <jrc### [at] msncom> wrote:
> HelveticaFanatic wrote:
> > I am modeling trains using Spline_Trans. Is there a way to average out the
> > points above each wheel set to get a position for the train so that it still
> > has the banking from Spline_Trans but shift over the side of the track so that
> > the wheels are above the tracks? Thanks.
> >
> >
> If I am understanding what you want, you can take points from along the
> spline on either side of a given point, together with the root point you
> can then use cross product (vcross(A,B) see the docs) to approximate a
> normal which which would reflect the banking of the spline.  You would
> 'normalize it of course and then multiply by the radius of your wheel to
> get the level where the axle would be.  If you don't quite understand
> what I mean, I would suggest you research what cross product is and work
> backward from there to a solution.
>
> -Jim

I think that this is just regular banking (I use Spline_Trans for that now). I
need to simulate a train where there are two wheel sets on the track. I need to
take the Spline_Trans translation and rotation for each wheel set to determine
the position of the train (the center point of the train of course will not be
over the center of the track, only the centers of the bogies). I want to carry
over the bank angle and make the train actually fit over the curve.

Post a reply to this message